From 800e58ae21796a472f39cd6d0601c87b297409af Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= Date: Tue, 23 Jun 2015 10:11:19 +0200 Subject: dell-laptop: Fix allocating & freeing SMI buffer page MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit b8830a4e71b15d0364ac8e6c55301eea73f211da upstream. This commit fix kernel crash when probing for rfkill devices in dell-laptop driver failed. Function free_page() was incorrectly used on struct page * instead of virtual address of SMI buffer. This commit also simplify allocating page for SMI buffer by using __get_free_page() function instead of sequential call of functions alloc_page() and page_address(). Signed-off-by: Pali Rohár Acked-by: Michal Hocko Signed-off-by: Darren Hart [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li --- drivers/platform/x86/dell-laptop.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c index e6c08ee8d46c..3d6759179f1c 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -216,7 +216,6 @@ static struct dmi_system_id __devinitdata dell_quirks[] = { }; static struct calling_interface_buffer *buffer; -static struct page *bufferpage; static DEFINE_MUTEX(buffer_mutex); static int hwswitch_state; @@ -714,11 +713,10 @@ static int __init dell_init(void) * Allocate buffer below 4GB for SMI data--only 32-bit physical addr * is passed to SMI handler. */ - bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32); + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32); - if (!bufferpage) + if (!buffer) goto fail_buffer; - buffer = page_address(bufferpage); ret = dell_setup_rfkill(); @@ -787,7 +785,7 @@ fail_backlight: fail_filter: dell_cleanup_rfkill(); fail_rfkill: - free_page((unsigned long)bufferpage); + free_page((unsigned long)buffer); fail_buffer: platform_device_del(platform_device); fail_platform_device2: -- cgit v1.2.3